1. Field Of The Invention
The invention is directed to a lathe having at least one base unit, comprising a drivable tool spindle which is rotatably supported in a spindle box which is displaceable on a machine bed in the direction of the longitudinal axis of the spindle, as well as a tool turret.
2. Scope Of The Prior Art
In a known lathe of this type (DE 38 34 342 A1) the spindle box is displaceable in the direction of two main axes, i.e. in the direction of the spindle axis and transversely relative to the latter, by means of a compound slide system, while the tool carrier is arranged so as to be stationary. This tool carrier comprises two turret heads which are rotatable around axes situated vertically relative to one another, one axis being arranged in the direction of the spindle axis and the other axis being arranged vertically with respect to the spindle axis. This requires a relatively high cost in the construction of the tool carrier. Further a compound slide system is required for the spindle box. It is known that the compound slide system has disadvantages with respect to high precision. Moreover this necessitates a relatively large machine bed on which to arrange the compound slide system with its guides, as well as the stationary tool carrier, which impairs access to the clamping chuck of the tool spindle because of its size. A decisive disadvantage consists in that the chips resulting from the machining of the workpieces fall on the large flat machine bed on which the compound slide system for the spindle box is provided, so that the guides of this compound slide system are impaired by the chips unless costly and trouble-prone protective devices are provided for the guides of the compound slide system. Protective devices for guides in lathes conventionally comprise cover plates which can slide together in the manner of a telescope and overlap one another with corresponding seals. These cover plates are exposed to a high degree of Wear because of this telescoping ability and are therefore prone to trouble.